How to make Zeroconf available on all interfaces [eth0/wlan0]

[jpiwek]

Hi,

I am playing with Zeroconf on an embedded linux system with a HTTP Server .
All interfaces have DHCP running.

How to configure Py-Zeroconf on all interfaces (eth0/wlan0) with DHCP on?
When I add the IP on eth0 e.g. 192.168.96.103 as in the code snippet below. Then it works accessing through PC on the networks, oherwise not.

addresses = [socket.inet_aton("192.168.96.103")]
   
info = ServiceInfo(
        "_http._tcp.local.",
        z_name,
        addresses=addresses,
        port=port,
        properties=desc,
        server=z_server,
)

[jstasiak]

Pass InterfaceChoice.All (or manually constructed list of addresses) as interfaces parameter when constructing Zeroconf. The addresses in ServiceInfo are are addresses that you advertise your service to be available at, they have no bearing on what interfaces do you send the advertisements to.

[jpiwek]

Ok thanks. However this means also that I have to change IP addresses that I advertise my services on each time those change e.g. due to new IP via DHCP, change to static IP,.... Is it right? Am 09.09.2020 um 18:41 schrieb Jakub Stasiak:

…

Pass |InterfaceChoice.All| (or manually constructed list of addresses) as |interfaces| parameter when constructing |Zeroconf|. The addresses in |ServiceInfo| are are addresses that you advertise your service to be available at, they have no bearing on what interfaces do you send the advertisements to. — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#296 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AHV57T3H7SBESWVCQ3RUARDSE6V3XANCNFSM4QUTKNMQ>.

[jstasiak]

If you're talking about the addresses used to specify the network interfaces for Zeroconf to use then every time there's a network configuration change (new interface, existing interface closes, IP address changes) the behavior of this library is undefined I think and you're better off killing the existing instance (using the Zeroconf.close() method) and starting a new one (with either updated interfaces list or InterfaceChoice.All)

[om26er]

Pass InterfaceChoice.All (or manually constructed list of addresses) as interfaces parameter when constructing Zeroconf. The addresses in ServiceInfo are are addresses that you advertise your service to be available at, they have no bearing on what interfaces do you send the advertisements to.

Wouldn't that have the same IP address published on all interfaces, which kind of is broken because if I publish my wlan IP on the ethernet interface as well then a client "looking" for my service on ethernet won't actually be able to connect because of wrong IP. I wonder if that's a bug in the library ?

[om26er]

For example if I publish a service with avahi, it publishes the "right" IP for each interface.

+ docker0 IPv6 serviceName                                   Web Site             local
+ br-b8bcb69e92fd IPv6 serviceName                                   Web Site             local
+ lxdbr0 IPv6 serviceName                                   Web Site             local
+  wlan2 IPv6 serviceName                                   Web Site             local
+ mpqemubr0 IPv6 serviceName                                   Web Site             local
+     lo IPv4 serviceName                                   Web Site             local
+ docker0 IPv4 serviceName                                   Web Site             local
+ br-b8bcb69e92fd IPv4 serviceName                                   Web Site             local
+ lxdbr0 IPv4 serviceName                                   Web Site             local
+  wlan2 IPv4 serviceName                                   Web Site             local
+ mpqemubr0 IPv4 serviceName                                   Web Site             local
= docker0 IPv6 serviceName                                   Web Site             local
   hostname = [KNUC.local]
   address = [fe80::42:27ff:fe71:eaa3]
   port = [5353]
   txt = []
= br-b8bcb69e92fd IPv6 serviceName                                   Web Site             local
   hostname = [KNUC.local]
   address = [fe80::42:99ff:fefe:fe23]
   port = [5353]
   txt = []
= lxdbr0 IPv6 serviceName                                   Web Site             local
   hostname = [KNUC.local]
   address = [fd42:76d1:bed3:17e4::1]
   port = [5353]
   txt = []
=  wlan2 IPv6 serviceName                                   Web Site             local
   hostname = [KNUC.local]
   address = [fe80::9e5f:c600:9b70:1113]
   port = [5353]
   txt = []
= mpqemubr0 IPv6 serviceName                                   Web Site             local
   hostname = [KNUC.local]
   address = [fe80::5054:ff:fe42:2398]
   port = [5353]
   txt = []
=     lo IPv4 serviceName                                   Web Site             local
   hostname = [KNUC.local]
   address = [127.0.0.1]
   port = [5353]
   txt = []
= docker0 IPv4 serviceName                                   Web Site             local
   hostname = [KNUC.local]
   address = [172.17.0.1]
   port = [5353]
   txt = []
= br-b8bcb69e92fd IPv4 serviceName                                   Web Site             local
   hostname = [KNUC.local]
   address = [172.18.0.1]
   port = [5353]
   txt = []
= lxdbr0 IPv4 serviceName                                   Web Site             local
   hostname = [KNUC.local]
   address = [10.153.181.1]
   port = [5353]
   txt = []
=  wlan2 IPv4 serviceName                                   Web Site             local
   hostname = [KNUC.local]
   address = [192.168.100.254]
   port = [5353]
   txt = []
= mpqemubr0 IPv4 serviceName                                   Web Site             local
   hostname = [KNUC.local]
   address = [10.119.114.1]
   port = [5353]
   txt = []

[webdevbyjoss]

hi all,
I have the same concern right now, @om26er did you actually figured this out?

[bdraco]

There is a PR open to add support for addresses per interface but its gone stale
#180

To make it work correctly we need a major architectural change as well
#806